Recently, various mobile information terminals and mobile game devices such as tablet-type information terminals and smart phones have become widely used. A secondary battery that is chargeable/dischargeable repeatedly is used as a power source of such a mobile electronic device. In addition, secondary batteries having a much larger capacity than a battery for mobile electronic devices have been increasingly desired. For example, hybrid vehicles that use both of a conventional internal combustion engine and an electric driving force, and electric vehicles that use a motor instead of the internal combustion engine are about to become widely used for saving energy or decreasing the carbon dioxide emissions. In such a situation, secondary batteries having higher characteristics, namely, a larger output, a larger capacity, a longer cycle life and the like are now desired for various uses.
A secondary battery stores charges by use of a redox reaction. Therefore, a substance reversibly oxidized and reduced, namely, an electricity storage material that stores charges, significantly influences these characteristics of a secondary battery. Conventional secondary batteries use metal materials, carbon, inorganic compounds and the like as electricity storage materials. In the case of, for example, a lithium secondary battery, which is in a wide use today, a metal oxide such as lithium cobalt oxide or the like, graphite, or the like is used as a positive electrode active material and a negative electrode active material, which are electricity storage materials.
It has been examined to use an organic compound as an electricity storage material instead of the inorganic material described above. An organic compound allows molecular design to be made in a more diversified manner than an inorganic material. Therefore, an active material formed of an organic compound is considered to have a variety of characteristics by molecular design. In addition, an organic compound is more lightweight than a metal material. Therefore, a secondary battery produced by use of an electricity storage material formed of an organic compound is considered to be lightweight.
For example, Patent Documents 1, 2 and 3 each disclose a secondary battery using a quinone-based compound as an electrode active material.